Watchmaker&#39;s compound lathe chuck



A. GOISDANKER.

WATCHMAKER'S COMPOUND LATHE CHUCK.

APPLICATION nun mm. 10. 1920.

1,41 1,082. Patented Mar. 28, 1922.

($58858 I i "7 M6Z {M Z7 ATTORNEYS TovwZ whom it may concern; ABRAHAM .Go'rsf UNITED PATEN came.

ABRA AM eo'rsnAivKER, o nitooKn-YN, NEW YORK.

' wnromvrixxn sfcoivironnn LATHEYQHUCK.

Be :it known 'that iI, V g DANKERystV: citizen of Russia,.;an'd airesident of the city :of NewI York; borough :of'Brooklyn, county of Kingsi-and 'State of New York, have'invente d a :new and Improved Watchmakers Compound Lathe Chuck, of which the following is a full,- clear, and esactidescription. V s I This 1 invention relates toiattachments' ior lathes,::and* has reference .IIIOIQi particularly to "a'chuck fOI'i'iL watchmakersilathe in which work: is clamped inner-plate which is separable from the chuck proper.v

I An object: of thisainventionis toprovide a device ofthe class lIIdiCELtGdWhlCh.-Wlll holdfine pieces of work :securely. Y

1 Another objectof this invention --islto' provide a watchmakers "latheflchuck in which the work is-held securely in. a clamping plate; which: in turn isclamped between thejaws of the chuckso' thatza larger'portion of the work maybe placed'insidethe chuck while the smalleraportioncf thefwork ison the outside of the chuck ina-position convenient for'the turning: operations.

Reference: is to be had to the accompanying drawing forming a ipartiof this: specification fin which 1 it-is 1 understood that the drawing illustrates only one example of the invention with certain modifications and in which Fi lathe dhuck,

Figure 2 is an end view of the lathe chuck with the clamping plate removed.

Figure 3 is an end view of the lathe chuck with the clamping plate in place.

Figure 4 is a section on the line 44 of 1 Figure 3.

Figure 5 is an elevation of the clamping plate removed from the chuck.

by numerals, 10 indicates the cylindrical stem of a watchmakers chuck which is provided on onev end with asection 11' smaller in diameter than the stem 10, and being re l-is an elevation of the improved I the work 21.

Y snecification of l'letterslatent. patented u gs 1.922, A pIicatlon flled llarch" 10,- 192p. Serial: so. 364,820.

provided with external threads12 which are adapted to fit in any standard lathe head not shown. The end Ofthestem 10. opposite 'the threads' 12, is-provlde'd with a-frustoconical'section' 18=-which is adapted to engage-a similar internal frusto-conical surface on'the'lathe head shown-1n Fig. 4, for

a purpose to'be hereinafter described. Ihe end of the stem =10 beyond the frusto-conical section -1'3 terminates in-a-cup 14 whichis also cylindrical. The stem 10, the 'frustoconical section 13, and the cup14are divided into afplurality of sectors, preferably three innumber, by -means --of slots 15 formed therein, said slots being parallel to theaxis of'= the'-stem10, and extending'to within a short distanceof the -sect-ion{11 ,of the stem 10. An annulargroove 16 is-formed on the inside: end'ofthe cup 14 so that "an oblique annularshoulde'r 17, is provided which-is adapted to engage a'circular disc 18 having substantially {the same diameteras said sl1oulde'r.- This plate 18 thin and "is stamped with a series of perforated "designs 19 which follo'w generally the radial direc- V tion o'f' the threesletsin the cup14. These perforationsl'9 converge in a hole 20in the center of'theplate '18 so that :when said plate is 1 pressed togethenit willhave a spongy character, and the edges of the hole 20 will grip any piece of work 21. When the section 11 is screwed into the lathe head, the

frusto-conical surfaces 13 will engage the similar surfaces on the lathe head so that the sectors of the cup 14 will be forced together and the oblique shoulder 17 will compress the'plate 18 and cause the edges of the iole 20 to securely grip the work 21.

' It is desirable to have the inside point 22 of the work 21 accurately centered, and for this purpose a tube 23 is accurately fitted to theinside ofthe section 11 and gradually tapers oil until the section of said tube ad- 'jacent the cup 14 has an outside diameter considerably smaller than the section of the tube 23 adjacent the threads 12, so that said tube will not interfere with the contraction of the cup 14. A spindle 24 is slidably fitted to the inside of the tube 23'and is provided 'curately centered.

is closed with a head 27 and a pin 28 smaller in diameter than the spindle 24c, and secured to said spindle, passesthrough the head 27 and extends beyond in order to be easily grasped by the hand so as to move the spindle 24 axially against the action of a spring 29 when putting the work 21 in place. This spring 29 surrounds the pin 28 and is adapted to provide a continuous pressure ofthe spindle 24 against the point 22 of the Work 21, so as to always maintainsaid work ac- The tube '23shou1d be secured inside the stem 10 by any suitable means such as solder 30. In order to observe the work 21 on, the inside of the cup 1 1, a plurality of openings 31 are provided in said cup, preferably one opening in each sector. Thus it is seen that the portion of the work 21 which is larger in diameter, may be'pla-ced on the inside of the'cup 14, while an outer point 32 is-in position on the out a side of the-cup 14 so that it may be trued up or may be machined in any other desired manner. a

' In the modified plate 18 shown in Figures 6, and '7, a plurality of perforations 19 are provided which ar somewhat difierent in shapethan theperforations 19 but serve a similar purpose. The central portion of the plate 18. has an offset 32 which is provided with a vhole 20 adapted to gripthe work.

This type of plate is especially adapted for use on small pieces of work. v In the modification shown. in- Figures-'8 and 9a plate 18,, is secured to a' bottomless cup 33, said plate and said cup being provided with slots 15 The cup 33 is adapted to fit into the inside of the cup 1 1 so that when said cup 14 is compressed around the cup 33, any extremely fine piece of work held by the plate 18,, will be absolutely'pre.

vented from etting out of alignment sln'ce the cup 33 WllIPIQVGDi) any slight shifting a V r of the plate 18 I would state in conclusion that while the illustrated example constitutes a practical embodiment of my invention, I do. not limit myself strictly to the ,mechanical details herein illustrated, since manifestly the same can becon'siderably varied without departure from the spirit of the invention as de- M fined in the appended claim.

Having thus described myinvention, I'

claim as new and desire to secureby Letters Patent: A Watchmakers chuck comprising a tubular member having one of its ends enlarged and hollow,said tubular member being longitudinally split to permit of contraction thereof, tubular member adapted-to be inserted within the firstmentioned tubular member and permanently secured therein, a wo rkrcentering member slidably inountedgin' the second-mentioned tubular "member,

hollow portion of the first-mentioned. tubular member'to retain the work inp'osition' in engagement with the centering member, substantially as described.

' ABRAHAM GOTSDANKER. 

